1. Field of Invention
The invention relates to a method for providing a portable flood barrier, in which flood barrier sections comprising two parallel, spaced apart, inflatable, elongated tubes joined by a waterproof web are placed on the ground with the side of one of the tubes facing the flooded area, and the other tube facing away from the flooded area. The invention also relates to a portable flood barrier section comprising two parallel, spaced apart, inflatable, elongated tubes. Further the invention relates to a portable flood barrier system comprising flood barrier sections.
2. Description of Prior Art
Flooding, caused by heavy rain, storms or melted snow, is a problem causing great economical damage and sometimes personal injury. For the purpose of flood control various types of barricades are built.
A well-known type of barricade is the sandbag barricade. This barricade is labour intensive and relatively slow to build. Thus there is a need for a portable barrier which can easily and quickly be erected.
Various types of portable flood barriers are known.
U.S. Pat. No. 4,981,392 describes a water inflatable structural module for constructing temporary dikes and related structures, comprising two identical elongated flattened cylinders which are sealed at opposite lateral ends to form a sealed, watertight chamber within a cylinder. The cylinders are joined by a flexible web. The cylinders can be inflated with water. Several modules may be stacked in an interlocking structure of any desired height without the use of fastening elements.
U.S. 5,645,373 describes a temporary flood control system comprising elongated flexible, inflatable, tubular ballast members secured to each other and adapted to be disposed on the ground for anchoring a generally sheetlike vertically extendable barrier wall or an inflatable tubular barrier member disposed above and connected to the ballast members. The ballast members are at least partly fillable with a dense ballast liquid, such as water, and may be inflated with pressurized air.
SE 503 551 describes a flood barrier comprising at least one water-filled chamber and a web or skirt which is kept in place by the floodwater. A similar construction in which the chamber is filled with air is also known.
De 3 810 493 describes a flood barrier comprising two inflatable hoses of different size, which are joined by a very short web. Both hoses may be partly filled with water. When used as a flood barrier, the larger hose is placed facing the flooded area, while the smaller hose is placed behind the larger hose as a support.
A general problem with these portable flood barriers according to prior art is their lack of resistance against lateral pressure from the flooded area, which may lead to lateral movement of the flood barrier and the subsequent breaking through of water. A further problem, particularly on soft or permeable ground, is water-flow from the flooded area underneath the barrier.
The object of the invention is to provide a method for providing a portable flood barrier, a portable flood barrier section and a flood barrier system comprising portable flood barrier sections which shall be quick and easy to erect, which shall withstand lateral pressure from the flood area, and in which the above mentioned problem of floodwater flowing underneath the barrier shall be reduced.
The objects are achieved by a method for providing a portable flood barrier, a portable flood barrier section and a flood barrier system as mentioned in the preamble, which are characterized by the features of the claims.
The invention relates to a method for providing a portable flood barrier, in which flood barrier sections comprising two parallel, spaced apart, inflatable, elongated tubes joined by a waterproof web are placed on the ground with the side of one of the tubes facing the flooded area, and the other tube facing away from the flooded area. According to the invention both tubes are inflated, and ballast water is filled on the web. This is done in an area in which flooding is expected to take place, preferably prior to the rising of the floodwater. Some water on the ground in which the barrier sections are placed will, however, normally not preclude the use of the invention. When the floodwater rises, the tube facing the flooded area floats in the floodwater and rises due to its buoyancy thereby forming a flood barrier.
The actual barrier is formed by the floating tube facing the flooded area. The method according to the invention thus relates to a principle, in which a physical phenomena created by the floodwater itself contributes to the formation of the barrier.
The barrier section and the flood barrier system according to the invention are favourable in the method for providing the flood barrier.